Access the full text.
Sign up today, get DeepDyve free for 14 days.
Loading next page...
/lp/unpaywall/developing-standards-for-environmental-toxicants-the-need-to-consider-wTwf0FRC4Q
References
References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.
- Publisher
- Unpaywall
- ISSN
- 0091-6765
- DOI
- 10.1289/ehp.8349247
- Publisher site
- See Article on Publisher Site
Abstract
Environmental Health Perspectives VoL 49, pp. 24 7-260, 1983 Developing Standards for Environmental Toxicants: The Need to Consider Abiotic Environmental Factors and Microbe- Mediated Ecologic Processes H. by Babich* and G. Stotzky* This article suggests and discusses two novel aspects for the formulation of standards for environ- mental toxicants. First, uniform national standards for each pollutant will be underprotective for some ecosystems and overprotective for others, inasmuch as the toxicity of a pollutant to the indige- biota is on the nous dependent physicochemical properties of the recipient environment. As the of need number chemicals that regulation is immense and as microbes appear to respond similarly to pollutant-abiotic factor interactions as do plants and animals, it is suggested that microbial as- be used to those abiotic factors most says initially identify that influence the toxicity of specific pol- lutants. Thereafter, additional studies using plants and animals can focus on these pollut- ant-abiotic factor interactions, and more meaningful standards can then be formulated more rapid- it ly and inexpensively. Second, is suggested that the response to pollutants of microbe-mediated ecologic processes be used to quantitate the sensitivity of different ecosystems to various toxicants. Such a quantification, expressed in terms of an "ecological dose 50%" (EcD50), could be easily incor- porated into the methodologies currently used to set water quality criteria and would also be appli- cable to setting criteria for terrestrial ecosystems. aquatic ecosystems. The Water Quality Criteria for Introduction 65 categories of chemicals considered toxic under the a of Federal 1977 Amendments to the CWA were set at levels Through variety statutes, including the Clean Air Act (CAA) of 1970, the Clean Water considered safe for human health and for various in Act (CWA) as amended 1977, the Federal Insecti- components of the aquatic biota (6-9). These criteria Act of cide, Fungicide, and Rodenticide (FIFRA) were later defined in terms of 129 specific priority Act to 1972, the Federal Water Pollution Control chemicals that are receive the maximum possible of the control in of (FWPCA) 1972, Resource Conservation and the discharge effluents (10). As there is Act of and the Toxic Sub- no Soil EPA not Recovery (RCRA) 1976, "Clean Act", has formulated criteria stances Act of the United or standards for toxicants occurring in terrestrial Control (TSCA) 1976, States Environmental Protection is environments. However, the level of toxicants in Agency (EPA) with the health and welfare of soils is indirectly monitored by the Federal Food, charged protecting of the environment from human beings and harmful Drug, and Cosmetic Act (FFDCA), which requires For exposures to toxic agents (1). example, as EPA and the Food and Drug Administration (FDA) EPA set required by the CAA, national primary to set action levels and tolerances for permissible to human health toxic of in In this some standards protect against levels toxicants foods. manner, of sulfur from con- levels atmospheric particulate matter, pollutants entering the food chain human dioxide, nitrogen oxides, carbon monoxide, taminated soils and then consumed by beings the hydrocarbons, photochemical oxidants and lead and are regulated (11). Furthermore, TSCA requires for or established national secondary standards only preproduction testing of any new chemical any dioxide In matter and sulfur (2-5). existing chemical with new uses which "may present particulate 1979, for in EPA set new criteria pollutants occurring an unreasonable risk to health or the environment," including both aquatic and terrestrial ecosystems. involved in de- This article discusses two aspects of Microbial of *Laboratory Ecology, Department Biology, related to basic veloping standards for toxicants as New York 952 Brown New NY University, Building, York, not to environmental safety but directly protecting 10003. 248 BABICH AND STOTZKY human health. First, the toxicity of a pollutant to Occupational Safety and Health (NIOSH), in its re- in view of the scientific literature on occupational ex- the indigenous biota is dependent, part, on the physicochemical properties of the recipient environ- posure to DDT that was prepared for the Occupa- ment. Because of the large number of chemicals tional Safety and Health Administration (OSHA), it is suggested that microbial noted that "female workers exposed to DDT and that require testing, be utilized as the initial screening system to other pesticides are reported to have suffered a sig- assays nificantly higher frequency of miscarriages and pre- identify those abiotic factors that influence most the these partum disorders than less exposed controls" (13). toxicity of different chemical pollutants. Once further The toxicity of an environmental contaminant to interactions have been identified, testing be with of the macro- the biota is influenced, in part, by the physicochemi- should representative species in natural habitats, as cal properties (Table 1) of the recipient environ- biota. Second, microorganisms ment. The toxicity of a pollutant may be reduced by well as many of the basic ecologic processes that are under the control of microbial activities and which the specific abiotic properties of one ecosystem, needed to maintain the of the biosphere, whereas in another ecosystem with different physi- are quality are sensitive to pollutants. However, when formulat- cochemical characteristics, the toxicity of an equiva- ing standards for the toxicants mandated by the lent dose of the same pollutant may be potentiated The should be consid- CAA and criteria for toxicants identified by the (14-17). latter environments EPA did not consider the potential adverse ered high risk environments. High risk groups and CWA, high risk environments are essentially similar effects of these toxicants on the various microbe- concepts: a high risk group is a population for which mediated ecologic processes (e.g., biogeochemical it is the toxicity of a pollutant is magnified; a high risk cycles, litter decomposition). Consequently, sug- of on mi- environment is an ecosystem in which the toxicity of gested that the adverse effects toxicants be a contaminant to the indigenous biota is magnified. crobe-mediated ecologic processes incorporated used to set environ- just as regulatory agencies recognize into the methodologies currently Consequently, The of a new for- high risk groups when establishing safe levels of con- mental standards. development the the dose taminants in foods, the environment, and the work- mulation, termed EcDsn (i.e., ecological is the concentration of a toxicant that place, similar consideration should be directed to 50%, which inhibits a microbe-mediated ecologic process by identifying high risk environments (18). would facilitate the of 50%), greatly incorporation Table 1. Physicochemical factors of an environment to data on the adverse effects of toxicants ecologic that can affect the toxicity of pollutants. involved in processes into the methodologies regula- Factor tory legislation. pH (acidity/alkalinity) Eh (oxidation-reduction potential) Physicochemical Factors: Aeration status (aerobic, microaerobic, anaerobic) Buffering capacity Modifiers of Pollutant Toxicity anionic composition Inorganic Environments cationic composition High Risk Inorganic Water content that establish Regulatory agencies permissible Clay mineralogy in the and the levels for toxicants foods, workplace, Hydrous metal oxides the existence of environment have recognized hy- matter Organic within the human Cation persensitive subgroups general exchange capacity Anion exchange capacity These individuals are population. hypersensitive Temperature risk and their is termed "high groups," sensitivity Solar radiation on the determined, depending specific toxicant, by Hydrostatic pressure con- such biotic factors as nutritional status, genetic Osmotic pressure and overall health. stitution, developmental stage, Most standards for toxicants are based on a se- For example, when setting action levels and toler- ries of assumptions, e.g., that the response of ro- for lead in foods and FDA ances (Pb) milk, recog- of and toddlers dents to a toxicant can be extrapolated to setting a nized the hypersensitivity infants for that toxicant suitable to protect human and in its health assessment for cadmium stan4ard (11), EPA, of that the of a few test species to a stated that "due to increased Cd beings; response (Cd), absorption toxicant can be extrapolated to setting a standard associated with certain nutritional deficien- being iron zinc that will protect the multiplicity of life in an entire insufficient levels of dietary (Fe), cies, e.g., of the ecosystem against that toxicant. If the assumptions (Zn), or calcium (Ca), older members popula- tion to be at even risk" than the are either incorrect or incomplete, such as result of are likely greater The National Institute for the failure to recognize the existence of high risk general population (12). STANDARDS FOR ENVIRONMENTAL TOXICANTS environments, then the regulations based similar ionic radii, for common sites on the cell on these will be to surface reduced the uptake and, hence, toxicity of assumptions inappropriate provide proper protection (19). A standard for an environmental toxi- Ni (28). The other abiotic factors listed in Table 1 cant that is based on only one set of abiotic environ- also differentially affect the toxicity of heavy metals mental variables may be overprotective or underpro- (15, 16). tective for ecosystems with differing physicochemi- An environment that may be high risk for one pollutant may be of low risk for a different pollut- cal properties (1, 15-17). ant. For example, the toxicity of Cd 29) and Zn To illustrate how physicochemical environmental (24, to factors influence pollutant toxicity, some heavy met- (30) microorganisms was decreased in acidic sys- tems, whereas that of Pb (25) and Ni (31, 32) was in- al pollutants will be used as examples. Physicochem- creased. There was no consistent relation between ical factors may influence the toxicities of heavy metals by affecting their (a) chemical speciation the toxicity of Mn and the pH of the medium (33), form, (b) chemicalphysical and and the toxicity of Hg was pH-independent (30). mobility (c) bioavaila- For in marine oc- The bility. example, environments, Cd Water Quality Criteria that were suggested curs primarily as a mixture of EPA indicate by that regulatory agencies have be- CdCl+/CdClJCdCl3-, whereas in acidic or neutral fresh waters it occurs gun, although only to a limited extent, to recognize as Cd2' (20). Similarly, in marine ecosystems, mer- that the toxicity of pollutants is on the dependent cury occurs primarily as a mixture of abiotic characteristics of the environment. HgCl3-/HgCl42, recipient whereas in fresh waters, depending on the it In formulating these criteria, EPA noted that "the pH, oc- curs as Hg2+, HgOH+, or Hg(OH)2. The different in- toxicity of certain less in some compounds may be organic speciation forms of these metals exert dif- waters because of differences in acidity, tempera- fering toxicities. Fungi tolerated Cd (21) and bacte- ture, water hardness, and other factors. Conversely, ria and bacteriophages tolerated Hg (22) better in some natural water characteristics increase may marine environments or in synthetic media with a the impact of certain pollutants." Consequently, sep- level in of chlorinity comparable to that occurring arate criteria were set for fresh and marine ecosys- oceans than in fresh waters or in synthetic media tems. Furthermore, as the toxicity of heavy metals with a limited chloride content, thus indicating the appears to be directly related to the degree of hard- lesser toxicities of the metal chloride species. ness in fresh waters, the criteria for Cd, Pb, Ni, Zn, Several abiotic factors limit the chemicalphysical and Be were formulated to reflect this Cu, Cr, mobility of heavy metals. Heavy metals that are im- the "sliding scale", i.e., as the hardness increases, mobilized, e.g., by sorption to clay minerals and level of the metals that can be tolerated by the bio- other or particulates by precipitation as phosphate, ta also increases (6-8). For for hardness lev- example, or carbonate, sulfide salts, are less readily available els of 50, 100, and 200 mg/L as the criteria CaCO3, for the biota. For uptake by example, incorporation for Cd are 0.012, 0.025, and 0.051 respectively ,Mg/L, of the montmorillonite clay minerals, and kaolinite, (9) into or soil synthetic media (23) (24) decreased the Although other environmental factors influence of to bacteria and The the of well of toxicity Cd fungi. incorpora- toxicity heavy metals (as as other pol- tion of or of EPA montmorillonite, attapulgite kaolinite, lutants), considered only the level of hardness or of carbonate or in fresh waters. For the were particulate organic matter, phos- metals that evaluated phate into a synthetic medium decreased the the allowable levels were in by EPA, higher marine of Pb to Nickel and were less than in fresh waters and in hard than in soft toxicity fungi (25). Cd waters, toxic to in hard water than in soft indicating that the or fungi water, highest risk, most fragile, eco- probably as a result of the higher levels of car- systems for metal would be soft heavy pollutants bonate and in the hard water fresh waters. The focus by EPA on hardness magnesium (26, 27). only Inorganic cations in various environ- reflects the lack of sufficient data to establish rela- present ments may influence the bioavailability and uptake tionships between other abiotic factors and pollu- of to the heavy metals biota. Competition for sites tant toxicity. "Although EPA recognizes that other on the cell surface between cations normally pres- water characteristics such as pH, temperature, or ent in a habitat and the cationic forms of specific degree of salinity (as in estuaries) may affect the the metals reduce the of the heavy may toxicity toxicity of some pollutants, the data base at this heavy metals. For example, the toxicity of Ni to time is not detailed enough for further specificity". marine fungi was reduced in the presence of seawa- EPA further will stated that these criteria not be ter. At the pH and chlorinity of seawater, Ni occurs "cast in concrete" will in but be updated future as Ni2+, and the reduction in Ni toxicity was corre- years when additional information becomes avail- with the content of lated Mg seawater, indicating able (6). that between Ni and which competition Mg, have There is, therefore, a critical need for additional 2.50 BABICH AND STOTZKY information on the influence of physicochemical fac- lack of such data that has hindered EPA in set- the tors on pollutant toxicity. The continued lack of ting criteria that are reflective of the different types such data will result in criteria that are inappropri- of ecosystems in the United States. The volume of ate (e.g., they will be either under- or overprotec- chemicals that need such evaluations-e.g., 129 just factors tive). Although the number of abiotic (Table for the Water Quality Criteria and an estimated 1) and their interactions that can modify pollutant 63,000 already in commerce plus approximately 1,000 new ones estimated annually (35), the limitations in toxicity may appear to be too complex to incorpo- laboratory facilities (especially if microcosms are rate successfully into standards that can easily be the expensive costs, and formulated and interpreted, not all these factors are used) and trained personnel, the need for "rapid" results has prompted our of equal importance in each ecosystem, and not all recommendation for using microbes as assay of the abiotic factors influence significantly the tox- systems to identify those abiotic factors that most icity of each pollutant. Most ecosystems possess dis- serve to significantly influence the toxicity of specific tinct abiotic factors that dominate and chemicals. characterize those environments. For example, alka- ion content are the domi- Microbes can serve as adequate monitors to pre- line pH and high inorganic characteristics of surface marine waters, and dict the response of the microbiota to a toxicant as nant cation exchange capacity, high organic matter influenced by abiotic factors. For example, a compi- high data of the responses to Cd by representa- content and acidic pH are the dominant characteris- lation of (Table 2), terrestrial tics of peat soils. Consequently, only the modifying tives of the aquatic macrobiota of specific (Table 4) indi- influence of the dominant abiotic factors macrobiota (Table 3) and microbiota need (as well as similar environments on pollutant toxicity probably cates common biologic responses in the decision-making contradictions in data) among these three distinct be considered regulatory Furthermore, for most chemicals, perhaps groups to Cd toxicity as influenced by abiotic fac- process. two or three abiotic factors will significantly tors. Microbial assays should be used initially to only singly or in their For example, pH and buffer- identify which environmental variables, modify toxicity. most directly affect the toxici- to be the abiotic factors that various combinations, ing capacity appear variables have influence the harmful effects of acid precipita- ty of a specific chemical. Once these most once the dominant abiotic been clearly identified for specific chemicals, further tion (34). Consequently, the the of a specific pollut- studies with representative species of macrobio- factors that influence toxicity criteria or standards can the of these factors in ta can be performed, and ant and relative importance their results. have been the en- be formulated on the basis of different ecosystems established, to the toxicity analyst need focus only on those abiotic The use of microbial assays predict vironmental human be- of a correlation of chemicals to the macrobiota, including factors. The establishment positive such as genetic the dominant abiotic factors of ecosystems ings, is not novel. Chronic effects, between or with those abiotic factors that most significantly diseases, birth defects and cancer, appear years to the toxi- the of a determined in even decades after the initial exposure modify toxicity pollutant (as must be screening) should aid in formulating cri- cant, and long-term studies using animals laboratory Such that would all ecosystems against that conducted to detect these latent responses. teria protect a single test to For example, if the toxicity of a pollutant studies are expensive: for example, pollutant. then distinct cri- of a chemi- is reduced by high pH and salinity, determine the potential carcinogenicity and fresh water eco- as as three at a cost of teria should be set for marine cal may require long years with the the risk environ- or more. Furthermore, the "world laborato- systems, latter being high $250,000 if the of a chemical is not for such chronic studies is estimated at ment. Conversely, toxicity ry capacity" or one criterion for both 500 chemicals/year, which is not sufficient to keep affected by pH salinity, an- fresh and marine water would perhaps provide suit- with the 700 to 1000 chemicals introduced pace to these diffi- for both nually into commerce (98). In response able protection ecosystems. best known the culties, short-term tests [the being Microbes as filamentous Assay Systems Ames' test (98)] with bacteria, yeasts, isolated mammalian cells Most research on chemical toxicants has focused fungi, plants, insects, and have been developed and are used as rapid and rela- the effects on human health of both on identifying inexpensive predictors of a chemical's poten- to a lesser chronic and tively acute and, extent, exposures tial to cause adverse chronic effects (99). on the molecular bases of the adverse identifying research to There therefore, a need for microbial assays, responses. There has been only limited is, and for their potential evaluate the interactions between pollutants not only to screen chemicals the resultant ef- on human but also to identify abiotic environmental factors and chronic effects beings, biota. It is factors most influence their toxicity in fects of these interactions on the general which abiotic STANDARDS FOR ENVIRONMENTAL TOXICANTS 25'1 Table 2. Physicochemical factors affecting the toxicity of cadmium to the aquatic biota. Environmental factor Comments Reference Temperature The estuarine fish, Fundulus heteroclitus was more sensitive to Cd at 200C than at 50C (36) Fingerlings of the freshwater perch, Perca fluviatilis, accumulated more Cd at 150C than at (37) 50C The estuarine crab, Paragrapsus gaimardii, was more sensitive to Cd at 190C than at 50C (38) The American oyster, Crassostrea virginica, accumulated more Cd at 200C than at 50C (39) Salinity Increasing the salinity decreased the toxicity of Cd to the grass shrimp, Palaemonetes pugio (40) The toxicity of Cd to the blue crab, Callinectes sapidus, decreased with increasing salinity (41) The toxicity of Cd to marine and estuarine crustaceans increased as the salinity was (42) decreased The marine mussel, Mytilus edulis, accumulated more Cd at 11 than at 30 0/00 salinity (43) Fundulus heteroclitus was more sensitive to Cd at 5 %0 salinity than at 15 to 35 0/0 salinity Water hardness The rainbow trout, Salmo gairdneri, tolerated more Cd as the water hardness was increased (44), (45) The fathead minnow, Pimephales promelas, tolerated Cd better in hard than in soft water (46) The toxicity of Cd to the brook trout, Salvelinus fontinalis, decreased as the water hardness (47) was increased The freshwater snail, Ampullaria paludosa, the catfish, Corydoras punctatus, and the guppy, (48) Lebistes resticulatus, accumulated more Cd in soft than in hard water Increasing the water hardness decreased the toxicity of Cd to eggs of the teleost, Oryzias (49) latipes Inorganic Simultaneous exposures to and reduced the of the (50) Pb, Zn, Cu uptake Cd by freshwater plant, cations Elodea nuttallii Ca decreased the of Cd to the marine (51) toxicity amphipod, Marinogammarus obtusatus Zn reduced the toxicity of Cd to Pimephales promelas (52 reduced the of the Ca toxicity and uptake Cd by the freshwater Gammarus (53) shrimp, pulex Inorganic reduced the of Pyrophosphate uptake Cd by Daphnia magna (54) anions Colloidal decreased the of to Organic organic particulates toxicity Cd the freshwater (55) crustacean, matter serrulatus Simocephalus Humic acid reduced the of Crassostrea uptake Cd by virginica and by Daphnia magna (39, 54) NTA reduced the of to Synthetic toxicity Cd Palaemonetes pugio (40) chelators EDTA and NTA reduced the of uptake Cd by Daphnia magna and by Crassostrea virginica 54) (39, EDTA, NTA, and DTPA reduced the of uptake Cd by the carp, Cyprinus carpio (56) EDTA reduced the uptake of Cd by the marine barnacle, Semibalanus balanoides (57) natural environments. Just as the results of micro- RCRA, TSCA). the However, continued health and to bial are used make more informed deci- welfare of human beings is dependent on maintain- assays to which chemicals should be examined fur- the sions as ing quality of the biosphere, as acknowledged in in the number of ther limited laboratories TSCA, which requires the preproduction testing of equipped for chronic studies with whole new performing toxicity chemicals and the testing of existing chemicals microbial should be used to deter- with new uses for their animals, assays potential hazards to the en- mine which abiotic interactions vironment. As stated in TSCA, factor-pollutant "It is the policy of should be studied further with the U.S. that adequate data representative spe- should be developed in cies of the macrobiota either artificial with respect to the effect of chemical substances simplified or in microcosms. and systems complex mixtures on health and the environment." Reg- ulatory agencies and environmental policy analysts to appear have narrowly defined "effect on the Protecting the Environment environment" as direct effects on the biotic compo- In Toto nents of the biosphere and have not considered the Microbe-Mediated Ecologic Processes effects of pollutants on ecologic processes mediated Attention by environmental re- policy-makers by the biotic and which component are necessary to for sponsible regulating toxicants has focused, and maintain the present state of the environment. For on human EPA rightfully so, health, as evidenced by the example, has stated that the Water Quality numerous federal statutes with were "to concerned limiting Criteria intended reflect the latest scientif- the of human to exposure beings harmful chemicals ic knowledge on the identifiable effects of pollut- (e.g., CAA, CWA, FIFRA, FWPCA, FFDCA, ants on public health and welfare, aquatic life, and BABICH AND STOTZKY Table 3. Physicochemical factors affecting the toxicity of cadmium to terrestrial plants. Environmental factor Comments Reference pH Uptake of Cd by oats and lettuce increased as the pH was decreased (58) Uptake of Cd by corn was independent of soil pH (59) to 7.5 reduced uptake of Cd by rice (60) Increasing the soil pH from 5.5 Chard and tomato accumulated more Cd when grown in acidic (pH 5.0 to 5.7) than in (61) alkaline (pH 7.5 to 7.8) soils pH from 4.5 to 6.4 reduced the uptake of Cd by ryegrass and oat (62) Increasing the soil Temperature of increased as the soil temperature was increased (63) Uptake Cd by soybeans from 0 to 10 0/00 but from 10 to 30 0/00 increased, the toxicity (64) Salinity Increasing the salinity decreased, of Cd to germination of seeds of Spartina alterniflora Cation exchange of oat was lower in soils with high than with low cation exchange capacities (65) Uptake Cd by capacity Water content Increasing the water content of the soil increased the uptake of Cd by barley (66) No synergistic interaction was noted between a drought stress and Cd for growth of An- (67) dropogon scoparius, Monardafistulosa, and Rudbeckia hirta Nitrogen content of Cd by fescue, grown in soil, was enhanced by nitrogen amendments (68) Uptake of Cd by bush bean, grown in a nutrient solution, was decreased by nitrogen (69) Uptake amendments in solution, was decreased by the ad- Inorganic Uptake of Cd by oat and lettuce, grown a nutrient (58) Al cations dition of Ca, K, or was noted between and Pb in reducing root growth, woody stem diameter (70) Synergism Cd growth, and foliage growth of American sycamore was noted between Cd and Pb in reducing vegetative growth of corn shoots (71) Synergism Al reduced the uptake of Cd by Hokus lanatus (72) Ni or Pb added to soil increased the uptake of Cd by ryegrass (62) Inorganic of oat, grown in soil, was decreased by the addition of phosphate Uptake Cd by (73) anions amendments decreased the uptake of Cd by corn seedlings (74) Phosphate to Table 4. Physicochemical factors affecting the toxicity of cadmium the microbiota. Environmental Reference factor Comments of pH Increasing the pH from 5 to 9 progressively increased the toxicity Cd to Aspergillus (29) to Bacillus niger, from pH 7 to 9 increased the toxicity of Cd cereus, Alcaligenes 8 to 9 the of to and Trichoderma viride, and from pH increased toxicity Cd faecalis, Agrobacterium tumefaciens, Nocardia paraffinae, and Rhizopus stolonifer; pH did not affect the of Cd to Streptomyces olivaceus toxicity of to of Increasing the soil pH from 5.1 to 7.2 increased the toxicity Cd mycelial growth (24) but not of Aspergillus fischeri Aspergillus niger of to Micrococcus luteus, Increasing the pH from 6 to 8 increased the toxicity Cd (75) Escherichia and Pseudomonas Clostridium coli, Staphylococcus aureus, perfringens, the of to Bacillus sub tilis aeruginosa; pH did not affect toxicity Cd from 6.5 to 8.3 increased the of Cd to Chlorella pyrenoidosa (76) Increasing the pH toxicity to decreased as the was increased from 7 to 8 Cd Chlorella pyrenoidosa pH (77) toxicity Navicula and the Chlorella (78) of Cd by the diatom, pyrenoidosa, green alga, Uptake increased as the pH was increased from 6 to 8 pyrenoidosa, the from 6 to 9 decreased the of Cd to the Nostoc (79) Increasing pH toxicity cyanobacterium, calcicola of the and The interaction towards mycelial growth fungi, Achyla sp. (30) pH-Cd toxicity on the of the medium was Saprolegnia sp., dependent composition growth (76) accumulated Cd faster at 250C than at 40C Temperature Chlorella pyrenoidosa (80) accumulated Cd faster at than at 50C Chlorella pyrenoidosa 15°C accumulated more Cd in soft than in hard water (48) Water hardness The alga, Nitellaflexilis, Penicillium Trichoderma (26) Rhizopus stolonifer, Scopulariopsis brevicaulis, vermiculatum, tolerated Cd better in hard than in soft water viride, Beauvaria sp., and Aspergillus niger STANDARDS FOR ENVIRONMENTAL TOXICANTS 253 Table 4 (Continued) Environmental factor Comments Reference Increasing the salinity above 45 0/oo reduced the toxicity of Cd to an unidentified marine Salinity (81) bacterium The toxicity of Cd to Rhizopus stolonifer, Trichoderma viride, Aspergillus niger, and Ar- (21) throbotrys conoides was reduced in medium amended with seawater at 20% or greater EDTA toxicity of Cd to the marine diatom, Ditylum brightwellii Synthetic decreased the (82) NTA reduced the toxicity of Cd to photosynthesis of a natural freshwater phytoplankton chelators (83) community EDTA the of to Klebsiella reduced toxicity Cd pneumoniae (84) EDTA the of Cd to Nostoc calcicola reduced toxicity (79) Organic Pyruvate, gluconate, citrate, and aspartate reduced the toxicity of Cd to Klebsiella (84) matter aerogenes Increasing the concentration of peptone decreased the toxicity of Cd to an unidentified (81) marine bacterium increased the of to Pseudomonas but not to Escherichia coli Citrate toxicity Cd sp. (85) Glutamine and cysteine decreased, but citrate increased, the toxicity of Cd to Nostoc (79) calcicola Humus reduced the toxicity of Cd to Selanastrum capricornutum (86) Montmorillonite and, to a lesser extent, kaolinite decreased the toxicity of Cd to Bacillus Clay (23) minerals megaterium, Agrobacterium tumefaciens, Nocardia corallina, Fomes annosus, Pholiota marginata, Botrytis cinerea, Aspergillus niger, Phycomyces blakesleeanus, Trichoderma viride, Chaetomium sp., Thielaviopsis paradoxa, Scopulariopsis brevicaulis, and in medium Schizophyllum sp. synthetic Montmorillonite and, to a lesser extent, kaolinite protected Penicillium vermiculatum, (24) Aspergillus asperum, Aspergillus niger, Aspergillus fischeri, and Trichoderma viride against Cd toxicity in soil was less toxic to Penicillium Penicillium Cation exchange Cd vermiculatum, asperum, Aspergillus niger, (20) and Cunninghamella echinulata when grown in an alkaline soil with capacity Aspergillus fischeri, 16 than in an soil with low a high cation exchange capacity (i.e., meq/100 g) acid a cation 8.2 exchange capacity (i.e., meq/100 g) Mg reduced the toxicity of Cd to growth of Escherichia coli Inorganic (87) cations Se reduced the of to of Haematococcus toxicity Cd growth capensis (88) The toxicity of Cd to growth of Aspergillus niger was decreased by Ca and Mg (89) Zn decreased the toxicity of Cd to growth of Euglena gracilis (90, 91) Mn inhibited the uptake of Cd by Chlorella pyrenoidosa (80) Cd and Pb interacted towards of a brackish water (92) synergistically inhibiting growth community phytoplankton Pb to inhibit in Cd and interacted synergistically photosynthesis and nitrogenase activity (93) Anabaena inequalis Zn and Pb interacted but and Ni interacted to Cd- synergistically, Hg antagonistically, (94) induced mitotic in Physarum polycephalum delay Zn and Cd interacted synergistically to inhibit growth of the marine diatoms, Thalassiosira (95) pseudonana and Skeletonema tricornutum; Zn interacted antagonistically to the toxicity of Cd to growth of Skeletonema costatum Inorganic Cd2+ was more than was an concentration inhibitory equivalent of Cd as Cd(CN)42- towards (96) anions growth of a mixed microbiota from activated sludge Increasing the chlorinity decreased the uptake of Cd by the estuarine alga, Chlorella salina (97) at a level to that in decreased the of to Chloride, equivalent occurring seawater, toxicity Cd (21) of sp., Oospora sp., Trichoderma viride, Aspergillus niger, mycelial growth Sepedonium and brevicaulis Rhizopus stolonifer, Scopulariopsis recreation." When considering "aquatic life," EPA of ni- chemical elements, the mineralization carbon, limited the to animals and including in needed to maintain scope plants, trogen, sulfur, and phosphorus this the unicellular As the ad- the of the the formation of or- category algae (&8). fertility biosphere, verse effects of toxicants on the microbiota, primari- matter chemo- and and the ganic by photosynthesis, ly on bacteria and fungi, were not considered when of and animal wastes. The hin- decomposition plant these EPA the "identi- drance of these microbe-mediated formulating criteria, ignored ecologic pro- fiable effects" of these toxicants on the numerous cesses by anthropogenic pollutants would greatly microbe-mediated ecologic-processes. affect the of the quality biosphere (14-16), eventually in terrestrial Microorganisms aquatic and ecosys- human health and welfare. For adversely affecting tems are involved in basic dynamically many ecolog- fungi and bac- example, microorganisms, primarily ic such as the cycling of processes, biogeochemical are involved in the decomposition of organic teria, 2541 BABICH AND STOTZKY matter, such as complex animal and plant tissues Ecologic Dose Fifty Percent (EcD50) In and excretory products. addition to being "Na- ture's sanitary engineers," microbial conversion of The extent of pollutant damage to some microbe- organic matter to inorganic materials (i.e., mineral- mediated ecologic processes can be measured effec- ization) is an important nutrient regeneration pro- tively in the laboratory. For example, heavy metals cess in aquatic (100) and terrestrial (101) ecosystems. have been shown to interfere with several microbe- Although most natural ecosystems contain an abun- mediated ecologic processes, such as the biogeo- dant supply of carbon, nitrogen, sulfur and phospho- chemical cycling of nitrogen (115, 122-135), sulfur rus, the major portion of these elements occurs as (107), phosphorus (108, 133, 134), and carbon (108, organic complexes that, as such, are unavailable for 109, 111-115, 129, 136-138); the decomposition of uptake by the phytobiota (102). Reductions in the plant litter (50, 109, 110, 117-119, 133, 139); photosyn- mineralization activities of microbes would initially thesis (83, 92, 115, 121, 140); and enzymatic activities affect the primary producer level, with plant (11, 119, 131-134, 141, 142). As these adverse effects growth being limited. As plants are the basic com- on ecologic processes can be quantified, it is sug- ponents of all food chains and webs, such perturba- gested that a formulation be derived, similar to the tions in plant growth would hinder the population (i.e., the dose that is lethal to 50% of the ex- LD. dynamics of herbivores, carnivores and omnivores, posed population) which has been used extensively including human beings. Thus, an adverse effect on to compute standards for exposures of human be- ings and the general biota to toxicants (143), to al- a microbe-mediated ecologic process such as miner- low environmental analysts and policy-makers easi- alization would, by a "domino effect," eventually im- ly to compute the extent of damage by a toxicant to pinge on the continued health and welfare of human beings. a microbe-mediated ecologic process and to compare the extent of damage by the same toxicant to a Microbes are sensitive to most pollutants (14-17), common in and an inhibition of microbial is accom- ecologic process different types of eco- activity Such a termed the panied by reductions in the ecologic processes that systems. formulation, "ecologic dose of they perform. The adverse effects of toxicants on fifty percent" and defined as the dose (EcD.) microbe-mediated ecologic processes have not, as a toxicant that decreases a specific microbe-medi- into ated of yet, been incorporated the formulations for ecologic process by 50% (other percentages criteria and standards of environmental computing decrease could also be used), would permit regulato- risks (18, 103). For example, although Cd adversely ry agencies to incorporate such data into the exist- affects microbe-mediated ing methodologies used in establishing environmen- many ecologic processes (Table 5), EPA did not consider these processes tal criteria and standards (18, 103). when formulating the Water Quality Criteria for The can be determined in a manner similar EcDO to that for in this metal (104) or for other toxicants (6-8). The need used the which a population, or LD., in in the case of the a microbe-mediated ecologic to examine environments a "holistic framework," EcDo, process, is exposed to progressively increasing lev- including microbe-mediated ecologic processes, has in els of a toxicant. The resulting data, when plotted been noted as a goal the 1980s for environmental as percent mortality for the LDso or as percent inhi- analysts (105). the of bition for the EcD50 versus the concentration of toxi- It is difficult to understand failure environ- to con- cant, should approximate a broad S-shaped curve mental policy analysts and policy makers from which the effects of on microbe- (144) or the can be com- sider the adverse toxicants LD,, EcD. when crite- puted. The LD50 test, which was developed initially mediated ecologic processes formulating in 1927 for the biological standardization of hazard- ria such as the Water Quality Criteria and stan- the Air ous drugs, has been incorporated into the routine dards such as National Secondary Quality The failure be due to the toxicological protocol for other classes of chemicals Standards. may inability now to compare easily, and, thus, to evaluate and incorpo- and is part of practically all Federal guidelines rate into the used to com- that regulate the toxicological testing of chemicals existing methodologies environmental criteria and standards the ex- (145). Currently, toxicologists determine values pute LD. of tent of damage by a toxicant to an ecologic process environmental chemicals for plant and animal of More en- of in different types ecosystems. probably, species representative specific ecosystems, and has not to the vironmental toxicology simply developed then, environmental policy-makers utilize LD. the where the need to consider an adverse af- values of the most sensitive species as the bases on point is It has which to formulate criteria. Similarly, EcD50 values fect on an ecologic process appreciated. have be- could be for different been stated that aquatic toxicologists only computed ecologic processes to address the effect" of toxicants stressed by a common pollutant, and the gun "ecological EcD. of value the most sensitive microbe-mediated eco- (106). FOR ENVIRONMENTAL TOXICANTS 255r STANDARDS Table 5. Effects of cadmium on some microbe-mediated ecologic processes in aquatic and terrestrial ecosystems. Ecologic Reference process Comments activity (107) Soil enzymatic 25 Cd/g soil inhibited arylsulfatase jimole (108) 25 soil inhibited the activities of acid and alkaline phosphatases jimole Cd/g activity (109) 10 ppm Cd inhibited soil respiration Carbon was decreased by addition of 10 ppm Cd + 1000 ppm Zn (110) mineralization Soil respiration (111) and soil respiration were reduced in a spruce needle mor con- Starch decomposition with Cu, Zn, Pb, and Cd emitted from a brass foundry taminated (112) mineralization in soil was inhibited by 100 ppm Cd Carbon of degradation in soil; no synergistic in- (113, 114) 1000 ppm Cd extended the lag phase glucose Cd and up to 10,000 ppm Zn or simulated acid teraction was noted between 1000 ppm in soil pH to 2.8 or 3.2 to glucose degradation rain causing a reduction oxidation in Chesapeake Bay water and sediment (115) 10 ppm Cd inhibited glucose of needle litter obtained from sites near metal-processing (116) Litter Rates of decomposition spruce Cu, Zn, Ni, and Cd were reduced as compared to litter obtained from decomposition industries emitting nonpolluted sites leaf litter from velutina, Smilacina stellata, and Populus (117) Decomposition rates of Quercus were reduced in a site contaminated with Cd, Zn, Pb and Cu tremuloides litter of leaves from Sassafras albidum, Quercus prinus, (118) Decomposition rates of consisting with Fe, Pb and Zn were lower as com- and Quercus rubra and contaminated Cd, Cu, from a site pared to similar litter nonpolluted inhibited of a Douglas-fir needle litter (119) 1000 Cd/g soil decomposition mg of Pinus taeda, Sassafras albidum, Quercus nigra, Quercus (120) Decomposition of leaves Prunus americana, and Acer rubrum was decreased in a freshwater laurifolia, with 5,Ag Cd/L ecosystem amended reduced photosynthesis of a brackish water phytoplankton community (92) Microbial 0.1 mg Cd/L inhibited photosynthesis in Chesapeake Bay water (115) photosynthesis 25 ppm Cd nM Cd inhibited growth of a marine phytoplankton community (121) inhibited of a freshwater phytoplankton community consisting (83) 10-6 M Cd photosynthesis mainly of diatoms Nitrogen cycle microbiota was reduced by 100 ,ug Cd/g soil (122) Denitrification Denitrification by the indigenous 0.01 to 0.04M inhibited nitrification in soil (123) Nitrification Cd Nitrification was reduced by Cd concentrations up to 400 jAg Cd/g soil but was enhanced at (124) levels from 400 to 2,500 jg Cd/g soil 5 soil inhibited nitrification (125) ,Amole Cd/g in at 1000 ppm Cd, nitrite accumulation was (126) 500 ppm Cd reduced nitrification soil; evident in water amended with 100 ppm Cd (115) Nitrification was reduced Chesapeake Bay inhibited fixation by soybean nodules containingRhizobium japonicum (127) Nitrogen 18jiM Cd nitrogen fixation of a Douglas-fir needle litter was decreased by amendments of 5 mM Cd/g (85) fixation Nitrogen soil be used to formulate criteria (18, logic process could stress. Second, the species selected to be assayed in importance to a natural 103). tests may be of limited LD. three distinct advantages over the when toxic effects are noted, deter- The EcDs has ecosystem, and are for of single must then be made as to whether the First, values populations minations LD. LD.. which are of uniform phys- presence of the species is critical to the continued species, usually size, age, and, there- functioning of the ecosystem. However, a greater iological and genetic constitution, etc., not the of natural risk and perturbation to the functioning of an eco- fore, do display heterogeneity Standards based on such single would be the inhibition or removal of an en- populations (146). system therefore, adequately tire functional group, such as decomposers, nitrogen species populations may not, The determina- the biosphere. Conversely, most microbe- fixers, or primary producers (147). protect of values would, therefore, have more rel- mediated are controlled by the tion EcDs ecologic processes than would values for predicting the combined metabolism of different species of bacte- evance LD. continued of stressed ecosystems. and fungi, and thus, an EcDs value reflects the functioning ria with the test, a direct comparison be- of a of populations to a Third, combined response variety LD5o 256 BABICH AND STOTZKY tween the sensitivities to a of toxicant species that and other environmental chemicals are still being dwell in different is not debated 149-158). ecosystems always possible. (19, The accumulation of sufficient For example, it may be necessary to data and compare the numerous attempts to apply the EcDw sensitivity to a pollutant of a marine with the and a fresh concept should, aid of statisticians, resolve water fish. These comparisons are difficult, as this problem. the possible effects resulting from the differences in the The concept can be applied to many areas EcD. environments are confounded by differences in of the environmental toxicology and is not limited to test species. However, as most microbe-mediated the Water Quality Criteria. There have been few ecologic processes are common to all ecosystems, a legislative or regulatory initiatives designed to pro- reduction in a in process one ecosystem by a toxi- tect soil as an ecosystem, even though pollutants cant can be with easily compared a similar reduc- cause may serious adverse effects on microbe-medi- tion by that toxicant in the same ecologic process ated ecologic processes in terrestrial ecosystems. but in a different For ecosystem. example, the level Consequently, the implementation of EcDs values in of toxicant inducing a 50% reduction in carbon min- risk analysis of aquatic ecosystems should have eralization in fresh waters can be to the compared immediate application to terrestrial ecosystems sim- level of that toxicant evoking an equivalent reduc- ilarly stressed by pollutants and, thus, may result in tion in carbon mineralization in marine waters the (18, establishment of Soil Quality Criteria. 103). it Although is suggested that the concept EcD,0 be into incorporated regulatory it decision-making, Conclusions is recognized that this concept needs to be more ful- ly analyzed and developed by the Cairns scientific commu- (146), in discussing future needs in the bio- nity. For example, a in logic assessment of pollutants, mentions two con- 50% reduction a basic ecolo- gic process may be a value that is too cepts: "pollutant realism" and "environmental extreme for real- ism." the continued of Pollutant realism is attained when those char- functioning a perturbed ecosystem acteristics or of the test compound that exist in the and, perhaps, an EcD10 would be more suit- EcD,, natural able. of environment are incorporated into the labo- Also, the a specific ecologic process- EcD. ratory test pollutant interaction not system. As EPA has begun to recognize should be viewed as a con- that stant value, as the the physicochemical properties of the recipient EcD50 value may depend on the environment length of exposure and on the influence the toxicity of a pollutant to properties of the test the ecosystem. For an indigenous biota, such abiotic factors should be example, value determined EcD. routinely after 2 days of which considered when formulating environmen- exposure, during a temporary tal lag may occur in the ecologic criteria and standards. However, at present, the process being studied, data base for such may be entirely different if interactions is insufficient, and determined after 2 laboratory tests using animals weeks of exposure, during which time and plants are too the stressed tedious and expensive. As populations may have to the influence of abiotic adapted the toxicant or may factors on the response of to have been replaced by microbes pollutants is populations having com- similar to that exhibited by more metabolic complex systems parable capabilities (113, 114, 126, 148). An (i.e., plants and animals), it is suggested that value for an micro- ecologic process-pollutant interac- EcDw bial assays be used initially to identify those tion may be different for hard fresh waters for abiotic than factors that most influence the toxicity of the vari- soft fresh waters. These "problems" are not unique ous pollutants. these to Once factors have been de- the EcD5. but also apply to the and it is com- LD., fined, additional studies mon for should be performed with toxicologists to determine an or or LD,o LD,, these factors using to macrobiotic species representa- determine an LD50 after 24, 48 or 96 hr or even tive of the stressed ecosystems and then after 2 weeks of not criteria exposure. Although often em- and standards formulated. Environmental phasized, the is also not a constant realism is but is depen- LDO attained when the tests account for all dent on at influenced aspects of or, least, by species, age, the ecosystem, including those ecologic processes weight, sex, genetic constitution, health, diet, meth- controlled by microbial activities. Microbe-mediated od of exposure, ambient seasonal vari- temperature, ecologic processes are critical to the continued func- ation, etc. (145). Another that will tioning of the biosphere, and some of the environ- aspect require considerable de- velopment is the of statisti- mentally oriented Federal statutes, such as application appropriate TSCA, cal designs and to the data used specify that adverse effects of pollutants on the en- analyses ecologic not for calculating values. This is also vironment must be determined. Thus, it is also rec- problem EcD. to the as the ommended that these unique sta- ecologic events be considered EcD5, concept, appropriate tistics for data and risk levels of in the regulatory process, and it is further sug- carcinogens LD,, STANDARDS FOR ENVIRONMENTAL TOXICANTS 257 18. Babich, H., gested that an formulation would be a useful Davis, D. L., and Trauberman, J. Environmen- EcD,0 tal quality criteria: some considerations. Environ. Manag. tool to simplify their incorporation. 5:191-205 (1981). 19. Hunter, W. G., and Crowley, J. J. Hazardous substances, Some of the research reported in this paper was supported, the environment, and public health: a statistical over- in part, by Grant R808329 from the United States Environ- view. Environ. Health Perspect. 32: 241-254 (1979). mental Protection Agency. The views expressed in this paper 20. Babich, H., and Stotzky, G. Effect of cadmium on the bio- are not necessarily those of the U.S. EPA. ta: influence of environmental factors. Adv. Appl. Micro- biol. 23: 55-117 (1978). 21. Babich, H., and Stotzky, G. Influence of chloride ions on REFERENCES toxicity of cadmium to fungi. Zbl. Bakt. Mikrobiol. Hyg. I Abt. Orig. C 3: 421- 426 (1982). 1. Garrett, T. L. The law of toxic substances. Environ. 22. Babich, H., and Stotzky, G. Differential toxicities of mer- 32: 279-284 Health Perspect. (1979). cury to bacteria and bacteriophages in and in sea lake 2. U.S. Environmental Protection Agency. National prima- water. Can. J. Microbiol. 25: 1252-1257 (1979). ry and secondary ambient air quality standards: notice of 23. Babich, H., and Stotzky, G. Reductions in the of toxicity proposed standards for sulfur oxides, particulate matter, cadmium to microorganisms by clay minerals. En- Appl. carbon monoxide, photochemical oxidants, hydrocarbons, viron. Microbiol. 33: 696-705 (1977). and nitrogen oxides. Fed. Reg. 36: 1502-1514 (1971). 24. Babich, H., and Stotzky, G. Effect of cadmium on fungi 3. U.S. Protection Environmental Agency. National prima- and on interactions between fungi and bacteria in soil: in- ry and secondary ambient air quality standards. Notice fluence of clay minerals and pH. Appl. Environ. Microbi- of proposed standards for sulfur oxides. Fed. Reg. 36: ol. 33: 1059-1066 (1977). 5867 (1971). 25. Babich, H., and Stotzky, G. Abiotic factors affecting the 4. U.S. Environmental Protection Agency. National prima- toxicity of lead to fungi. Appl. Environ. Microbiol. 38: ry and secondary ambient air quality standards. Fed. 506-514 (1979). Reg. 36: 8186-8201 (1971). 26. Babich, H., and Stotzky, G. Influence of water hardness U. 5. S. Environmental Protection Agency. Lead. Proposed on the of toxicity heavy metals to fungi. Microbios Let- national ambient 42: air quality standard. Fed. Reg. ters 16: 79-84 (1981). 63076-63086 (1977). 27. Babich, H., and Stotzky, G. Components of water hard- U.S. Environmental Protection Agency. Water quality ness which reduce the of toxicity nickel to fungi. Micro- criteria. Fed. 44: 15926-15981 Reg. (1979). bios Letters 18: 17-24 (1981). 7. U.S. Environmental Protection Water Agency. quality Babich, H., and Stotzky, G. Nickel toxicity to estua- criteria, availability. Fed. Reg. 44: 43660-43697 (1979). rine/marine fungi and its amelioration by magnesium in 8. U.S. Environmental Protection Agency. Water quality water. sea Water, Air, Soil Pollut., in press. criteria, availability. Fed. Reg. 44: 56628-56657 (1979). Babich, H., and Stotzky, G. Sensitivity of various bacte- 9. U.S. Environmental Protection Agency. Water quality ria, including actinomycetes, and fungi to cadmium and criteria documents; availability. Fed. Reg. 45: 79318- the influence of pH on sensitivity. Appl. Environ. Micro- 79379 (1980). biol. 33: ). 681-695 ( 10. Branson, D. R. Prioritization of chemicals according to 30. Babich, H., and of Stotzky, G. Influence chemical specia- the degree of hazard in the aquatic environment. Envi- tion on the of metals to the toxicity heavy microbiota: In: ron. Health Perspect. 34: 133-138 (1980). Aquatic Toxicology, Advances in Environmental Science 11. Babich, H., and Davis, D. L. Food tolerances and action and 0. in Technology (J. Nriagu, Ed.), Wiley, New York, levels: do they adequately protect children? BioScience press. 31: 429-438 (1981). 31. Babich, H., and Nickel to Stotzky, G. toxicity microbes: 12. U.S. Environmental Protection Agency. Health Assess- effect of and for acid Environ. pH implications rain. Res., for ment Document Cadmium. Environmental Criteria in press. Assessment North and Office, Research Triangle Park, 32. Babich, H., and G. Nickel to Stotzky, toxicity fungi: influ- Carolina, 1979. ence of environmental factors. Ecotoxicol. Environ. Safe- for 13. National Institute Occupational Safety and Health. ty 6: 577- 589 (1982) DDT. Special Occupational Hazard Review. United 33. Babich, H., and G. to Stotzky, Manganese toxicity fungi: of States Department Health, Education, and Welfare, influence of pH. Bull. Environ. 27: Contam. Toxicol. 474- Rockville, Maryland, 480 (1981). 14. and G. Air and microbial Babich, H., Stotzky, pollution 34. Babich, H., Davis, D. L., and Stotzky, G. Acid precipita- CRC Crit. Rev. Environ. 4: 353-421 ecology. Contr. (1974). tion: causes and consequences, Environment 22: 6-13, 40- 15. Babich, H., and Stotzky, G. Environmental factors that (1980). influence the toxicity of heavy metals and gaseous pollu- Anonymous. EPA and toxic substances law: dealing with to 8: tants microorganisms. CRC Crit. Rev. Microbial. 99- 202: uncertainty. Science 598-600 (1979). 145 (1980). Eisler, R. Cadmium poisoning in Fundulus heteroclitus H. and 16. Babich, Stotzky, G. Physicochemical factors that and other (Pisces: Cyprinodontidae) marine organisms. J. affect the toxicity of heavy metals to microbes in aquatic Fish. Res. Bd. 28: 1225-1234 Can. (1971). In: habitats. Aquatic Microbial Ecology, Proceedings of 37. Edgren, M., and M. Notter, Cadmium uptake by finger- the American Society for Microbiology Conference (R. R. lings of perch (Perca fluviatilis) studied by Cd-115m at of Colwell and J. Eds.) Sea Foster, University Maryland two different temperatures. Bull. Environ. Contam. Grant 181-203. Publication, College Park, MD, 1980, pp. Toxicol. 24: 647-651 (1980). 17. and H. Mediation of the of Stotzky, G., Babich, toxicity 38. K. Sullivan, J. Effects of salinity and on the temperature to microbes the pollutants by physicochemical composi- acute toxicity of cadmium to the estuarine crab, tion of the environment. In: recipient Microbiology- Paragrapsus gaimaridii (Milne Austral. J. Edwards). 1980 American for Micro- (D. Schlessinger, Ed.), Society Mar. Freshwater Res. 28: 739-748 (1977). biology, Washington, DC, 1980, pp. 352-354. 258 BABICH AND STOTZKY Hung, Y.-W. Effects of temperature and chelating agents the complexation of soluble cadmium, zinc, and copper. on cadmium uptake in the American oyster. Bull. Envi- Mar. Ecol. Prog. Ser. 2: 143-153 (1980). ron. Contam. Toxicol. 28: 546-551 (1982). 58. John, M. K. Interrelationships between plant cadmium and uptake of some other elements from culture solu- 40. Sunda, W. G., Engel, D. W., and Thoutee, R. M. Effect of speciation on toxicity of cadmium to grass tions by oats and lettuce. Environ. Pollut. 11: 85-95 chemical shrimp, Palaemonetes pugio: importance of free cadmi- (1976). um. Environ. Sci. Technol. 12: 409-413 (1978). 59. Jones, R. L., Hinesley, T. D., Ziegler, E. L., and Tyler, 41. Frank, P. M., and Robertson, P. B. The influence of salini- J. J. and zinc contents of corn leaf and grain Cadmium ty on toxicity of cadmium and chromium to the blue crab, produced by sludge-amended soil. J. Environ. Qual. 4: Callinectes sapidus. Bull. Environ. Contam. Toxicol. 21: 509-514 (1975). 74-78 (1979). 60. Bingham, F. T., Page, A. L., and Strong, J. E. Yield and 42. Jones, M. B. Synergistic effects of salinity, temperature, cadmium content of rice grain in relation to addition and heavy metals on mortality and osmoregulation in rates of cadmium, copper, nickel, and zinc with sewage marine and estuarine isopods (Crustacea). Mar. Biol. 30: sludge and liming. Soil Sci. 130: 32-38 (1980). 13-20 (1975). 61. Mahler, R. J., Bingham, F. T., Sposito, G., and Page, L. Effects of cadmium on the intercellular pool 43. Briggs, R. A. L. Cadmium-enriched sewage sludge application to in Mytilus edulis. Bull. Environ. Con- of free amino acids acid and a calcareous soils: relations between treatment, tam. Toxicol. 22: 838-845 (1979). cadmium in saturation extracts, and cadmium uptake. J. 44. Brown, V. M. The, calculations of the acute toxicity of Environ. Qual. 9: 359-364 (1980). mixtures of poisons to rainbow trout. Water Res. 2: 723- 62. Allinson, D. W., and Dzialo, C. The influence of lead, cad- 733 (1968). mium, and nickel on the growth of ryegrass and oats. 45. Marchetti, R., and Vailati, G. Influence of Soil 62: 81-89 (1981). Calamari, D., Plant water hardness on cadmium toxicity to Salmo gairdneri 63. Haghiri, R. Plant uptake of cadmium as influenced by ca- Rich. Water Res. 14: 1421-1426 (1980). tion exchange capacity, organic matter, zinc, and soil 46. Pickering, Q. H., and Henderson, C. The acute toxicity of temperature. J. Environ. Qual. 3: 180-183 (1974). some heavy metals to different species of warm water 64. Mrozek, E., Jr. Effect of mercury and cadmium on germi- fishes. Int. J. Air Water Pollut. 10: 453-463 (1966). nation of Spartina alterniflora Loisel seeds at various 47. J. S. J., and Oliver, W. S. Influences of salinities. Environ. Exp. Bot. 20: 367-377(1980). Carroll, J., Ellis, toxicity of cadmium K. maxima of soils as mea- hardness constituents on the acute 65. John, M. Cadmium adsorption isotherm. Soil Sci. 52: 343- to brook trout (Salvelinus fontinalis). Bull. Environ. Con- sured by the Langmuir Can. J. tam. Toxicol. 22: 575-581 (1979). (1972). B. of and zinc from sludge 48. Kinkade, M. L., and Erdman, H. E. The influence of hard- 66. Kirkham, M. Uptake cadmium different ness components (Ca2+ and Mg2+) in water on the uptake by barley grown under four sludge irrigation 4: 423-426 (1975). and concentration of cadmium in a simulated freshwater regimes. J. Environ. Qual. R. Effects of cadmium and a ecosystem. Environ. Res. 10: 308-313 (1975). 67. Miles, L. J., and Parker, G. on the toxicity of and yield of 49. Michibata, H. Effect of water hardness one-time drought stress on survival, growth, to the of the teleost Oryzias latipes. Bull. Environ. Qual. 9: 278-282 (1980). cadmium egg native plant species. J. Toxicol. 27: 187-192 (1981). J. J. Nitrogen effects on Environ. Contam. 68. Giordano, P. M., and Mortvedt, K., Takeshita, S., and Wada, Y. The uptake of heavy metals in sewage 50. Nakada, M., Kukaya, mobility and plant of heavy metals in the submerged plant to soil columns. Environ. 5: 165- accumulation sludge applied J. Qual. Bull. Environ. Contam. Toxicol. 22: 21- 168 (1976). (Elodea nuttallii). 27 (1979). 69. R. and Huckabee, J. W. Ecological studies of Smith, H., D. and Frain, J. W. Cadmium toxicity in the fate, and consequences of cadmium. In: 51. Wright, A., movement, obtusatus: effect of external calcium. Element Fulkerson and Marinogammarus Cadmium-The Dissipated (W. Environ. Res. 24: 338-344. H. E. Goeller, Eds.), Oak Ridge National Laboratory, Oak Eaton, J. G. Testimony in the matter of proposed toxic pp. 278-307. 52. Ridge, TN, 1973, effluent standards for aldrin-dieldrin et al. Fed- 70. R. and Bazzaz, F. A. Growth reduction in pollutant Carlson, W., eral Water Pollution Control Act Amendments (307), American sycamore (Plantanus occidentalis L.) caused by 12: 243-253 Docket No. 1 (1974). Pb-Cd interactions. Environ. Pollut. (1977). W. The effect of calcium on and D. E. Interaction 53. Wright, D. A., and Frain, J. 71. Miller, J. E., Hassett, J. J., Koeppe, of lead and cadmium on metal and growth of plant cadmium toxicity in the freshwater amphipod, Gamma- uptake Toxicol. 10: 321- J. Environ. 6: 18-20 rus pulex (L.). Arch. Environ. Contam. species. Qual. (1977). 72. S. A. J. M., Morgan, A. N., Salmon, 328 (1981). McGrath, P., Baker, be- Their W. J., and Williams, M. The effects of interactions 54. Poldoski, J. E. Cadmium bioaccumulation assays. of two met- in Lake Superior tween cadmium and aluminum on the growth relationships to various ionic equilibria al-tolerant races of Holcus lanatus L. Environ. Pollut. water. Environ. Sci. Technol. 13: 701-706 (1979). 23A: 267-277 (1980). 55. J. P., Jr., Leversee, G. J., and Williams, D. R. Ef- Giesy, 73. M. K. of cadmium and its distri- fects of naturally occurring aquatic organic fractions John, Uptake soil-applied serrulatus bution in radishes. J. Plant Sci. 52: 715-719 (1972). on cadmium toxicity to Simocephalus (Daph- Can. Water Res. 11: 74. B. and Lindsay, W. L. Influence nidae) and Gambusia affinis (Poeciliidae). Street, J. J., Sabey, R., of sludge, and incuba- 1013-1021 (1977). phosphorus, cadmium, sewage pH, Effect of NTA, and tion time on the and plant uptake of cadmium. 56. Muramoto, S. complexans (EDTA, solubility on the to concentrations of cadmi- J. Environ. 7: 286-290 (1978). DTPA) exposure high Qual. and lead. Bull. Environ. Contam. Toxi- 75. and Pekkanen, T. J. The effect of pH and um, copper, zinc, Korkeala, H., col. 25: 941-946 buffer on the toxicity of cadmium (1980). potassium phosphate E. and 57. P. A. Wiggins, A., Jackson, for bacteria. Acta Vet. Scand. 19: 93-101 (1978). Rainbow, S., Scott, G., on the accumulation of R. W. Effect of agents 76. J. and B. A. W. Effect of physical and chelating Gipps, F., Coller, balanoides and cadmium the barnacle Semibalanus culture conditions on of cadmium by Chlorella py- by uptake STANDARDS FOR ENVIRONMENTAL TOXICANTS 259 renoidosa. Austral. J. Mar. Freshwater Res. 31: 747-755 zinc and cadmium on growth and uptake in some marine (1980). diatoms. J. Exp. Mar. Biol. Ecol. 42: 39-54 (1980). 77. Hart, B. A., and Scaife, B. D. Toxicity and bioaccumula- 96. Cenci, G., and Morozzi, G. Evaluation of the toxic effect in Chlorella pyrenoidosa. Environ. Res. tion of cadmium of Cd2+ and Cd(CN)42 ions on the growth of mixed micro- 14: 401-413 (1977). bial population of activated sludge. Sci. Total Environ. 7: 78. Hassett, J. M., Jennett, J. C., and Smith, J. E. Microplate 131-143 (1977). technique for determining accumulation of metals by al- 97. Wong, K. H., Chan, K. Y., and Ng, S. L. Cadmium uptake gae. Appl. Environ. Microbiol. 41: 1097-1106 (1981). by the unicellular green alga Chlorella salina Cu-1 from 79. Singh, S. P., and Pandey, A. K. Cadmium toxicity in a cy- culture media with high salinity. Chemosphere 8: 887-891 anobacterium: effect of modifying factors. Environ. Exp. (1979). Bot. 21: 257-265 (1981). 98. Ames, B. N. Identifying environmental chemicals causing 80. Hart, B. A., Bertram, P. E., and Scaife, B. D. Cadmium mutations and cancer. Science 202: 587-593 (1979). transport by Chlorella pyrenoidosa. Environ. Res. 18: 99. U.S. Environmental Protection Agency. Environmental 327-335 (1979). Assessment. Short-term Test for Carcinogens, Muta- gens, and other Genotoxic Agents, Research Triangle 81. Gauthier, M. J., and Flatau, G. N. Etude de l'accumula- Park, North Carolina, 1979. tion du cadmium par une bacterie marine en fonction des 100. Rhineheimer, G. Aquatic Microbiology, Wiley, New conditions de cultures. Chemosphere 9: 713-718 (1980). York, 1971. 82. Canterford, G. S., and Canterford, D. R. Toxicity of brightwellii 101. Alexander, M. Microbial Ecology, Wiley, New York, heavy metals to the marine diatom Ditylum (West) Grunowi: correlation between toxicity and metal 1971. Mar. Biol. Assoc. 60: 227-242 (1980). 102. Stotzky, G. Activity, ecology, and population dynamics of speciation. J. U.K. 83. Skogheim, 0. K., Hindar, A., and Abraham- microorganisms in soil. CRC Crit. Rev. Microbiol. 4: 59- Hongve, D., sen, H. Effects of heavy metals in combination with 137 (1972). NTA, humic acid, and suspended sediment on natural 103. Babich, H. Holistic approach to environmental quality phytoplankton photosynthesis. Bull. Environ. Contam. standards. Toxic Subst. J., in press. Toxicol. 25: 594-600 (1980). 104. U.S. Environmental Protection Agency. Cadmium. Ambi- 84. Pickett, A. W., and Dean, A. C. R. Cadmium and zinc sen- ent Water Quality Criteria. PB 292 423. Office of Water Planning and sitivity and tolerance in Klebsiella (Aerobacter) aero- Standards, Washington, DC, 1979. Microbios 15: 79-91 105. White, G. F. genes. (1979). Environment. Science 209: 183-190 (1980). B. of on 106. Macek, M. J. fact or fiction? Environ. 85. Lighthart, Effects certain cadmium species pure Aquatic toxicology: of Antonie Health Perspect. 34: 159-163 and litter populations microorganisms. van (1980). 161-167 107. Al-Khafaji, A. A., and Tabatabai, M. A. Effects of trace Leeuwenhoek 46: (1980). E. T. The effect of humus on the biolog- elements on arylsulfatase activity in soils. Soil Sci. 127: 86. Gjessing, aquatic of Arch. 91: 144-149 129-133 (1979). ical availability cadmium. Hydrobiol. 108. Juma, N. G., and Tabatabai, M. A. Effects of trace ele- (1981). 87. P. E. Ion antagonisms in micro- ments on phosphatase activity in soils. Soil Sci. Soc. Am. Abelson, H., and Aldous, J. 41: 343-346 (1977). organisms: interference of normal magnesium metabo- and manganese. J. 109. Bond, H., Lighthart, B., Shimabuku, R., and Russell, L. lism by nickel, cobalt, cadmium, zinc, Some of lit- effects cadmium on coniferous forest soil and Bacteriol. 60: 401-413 (1950). ter T. of the of microcosms. Soil Sci. 121: 278-287 (1976). 88. Hutchinson, C. Comparative studies toxicity 110. Chaney, W. their in- R., Kelley, J. M., and Strickland, R. C. Influ- heavy metals to phytoplankton and synergistic ence of Water Pollut. 8: 68-90 cadmium and zinc on carbon dioxide evolution teractions. Res. Canada (1973). from Sur du calcium litter and soil from a black oak forest. J. Environ. 89. Laborey, F., and Lavollay, J. l'antitoxicite 7: et a du dans la crois- Qual. 115-119 (1978). du magnesium l'e'gard cadmium, sance C. R. Acad. Sci. 284D: 639-642 Ebregt, A., and Boldewijn, J. M. A. M. Influence of d'Aspergillus niger. in (1977). heavy metals spruce forest soil on amylase activity, evolution from 90. and S. Effect of cadmium on CO2 and soil Plant Soil Nakano, Y., Abe, K., Toda, starch, respiration. 47: 137-148 growth of Euglena gracilis grown in the zinc-optimum (1977). 112. A. H. range. J. Environ. Sci. Health 16A: 175-187 (1981). Cornfield, Effects of addition of 12 metals on car- bon dioxide release incubation of 91. Nakano, Y., Okamoto, K., Toda, S., and Fuwa, K. Toxic during an acid sandy in zinc soil. Geoderma 19: 199-203 effects of cadmium on Euglena gracilis grown (1977). sufficient media. Biol. 42: 113. Bewley, R. J. and G. Effects of zinc and cad- deficient and zinc Agr. Chem. F., Stotzky, 901-907 mium on microbial activity in soil: influence of clay min- (1978). 92. K. and effects of erals. Sci. Total Environ., in press. Pietilainen, Synergistic antagonistic cadmium on aquatic primary productivity. In: 114. Bewley, R. J. F., and Stotzky, G. Effects of combinations lead and of International Conference on Metals in the Envi- simulated acid rain and cadmium or zinc on microbial Heavy in soil. Environ. in Institute for Environ- activity Res., press. ronment, Symposium Proceedings, 115. A. University of Toronto, Ontario, Canada, Mills, L., and Colwell, R. R. Microbiological effects of mental Studies, metal ions in Vol. II, Part 861-873. Chesapeake Bay water and sediment. Bull. 2, 1975, pp. Environ. and C. T. The effect of Contam. Toxicol. 18: 99-103 (1977). 93. Stratton, G. W., Corke, mercuric, and nickel ion combinations on a al- Tyler, G. Heavy metals pollute nature, may reduce pro- cadmium, blue-green Ambio 1: 53-59 8: 731-740 (1979). ductivity. (1972). ga. Chemosphere 117. and R. and 94. G. and I. A. A cellular Inman, J. C., Parker, G. Decomposition heavy Chin, B., Lesowitz, S., Bernstein, metal of forest litter in northwestern Indiana. model for studying accommodation to environmental dynamics Environ. Pollut. 17: 39-51 stressors: and by cadmium and (1978). protection potentiation 118. L. Forest leaf litter in the vi- other metals. Environ. Res. 16: 432-442 (1978). Strojan, C. decomposition of a zinc smelter. 32: 203-212 95. G. and A. Heavy metal tol- cinity Oecologia (1978). Braek, S., Malnes, D., Jensen, 119. B. Effects of divalent metal chlorides on erance of marine phytoplankton. IV. Combined effect of Spalding, respi- 260 BABICH AND STOTZKY ration and extractable enzymatic activities of Douglas-fir 138. Bhuiya, M. R. H., and Cornfield, A. H. Effects of addition needle litter. J. Environ. 8: Qual. 105-109 (1979). of 1000 ppm Cu, Ni, Pb, and Zn on carbon dioxide release 120. Giesy, J. P., Jr. Cadmium of inhibition leaf decomposition during incubation of soil alone and after treatment with in an aquatic microcosm. 6: Chemosphere 467-475 (1978). straw. Environ. Pollut. 3: 173-177 (1972). 121. Hollibaugh, J. T., Seibert, D. L. R., and 139. Doelman, P., and Thomas, W. H. A Haanstra, L. Effects of lead on the de- comparison of the acute toxicities of ten composition of heavy metals to organic matter. Soil Biol. Biochem. 11: phytoplankton from Saanich Inlet, B.C., Canada. Estuar. 481-485 (1979). Coast. Mar. Sci. 10: 93-105 140. Davies, A. G., and Sleep, J. A. (1980). Photosynthesis in some 122. Bollag, J. M., and Barabasz, W. Effect of heavy metals on British coastal waters may be inhibited by zinc pollution. the denitrification process in soil. J. Environ. Qual. 8: Nature 277: 292-293 (1979). 196-201 (1979). 141. Doelman, P., and Haanstra, L. Effect of lead on soil respi- 123. Lees, H., and Quastel, J. H. Biochemistry of nitrification ration and dehydrogenase activity. Soil Biol. Biochem. 11: in soil. Biochem. J. 40: 815-823 (1946). 475-479 (1979). 142. Pacha, J. 124. Tyler, G., Monsjo, B., and Nilsson, B. Effects of cadmium, The effect of zinc and copper on the soil enzy- lead, and sodium salts on nitrification in a mull soil. Plant matic activity. Acta Biol. Katowice 9: 128-142 (1980). Soil 40: 237-242 143. (1974). Matthews, P. J. Toxicology for water scientists. J. Envi- 125. Liang, C. N., and Tabatabai, M. A. Effects of trace ele- ron. Manag. 11: 1-16 (1980). ments on nitrification in soils, J. Environ. Qual. 7: 291-293 144. Hayes, W. J., Jr. Toxicology of Pesticides, Williams and (1978). Wilkins, Baltimore, MD, 1975. 126. Bewley, R. J. F., and Stotzky, G. Effects of cadmium and 145. Zbinden, G., and Flury-Roversi, M. Significance of the simulated acid rain on ammonification and nitrification in LD5, test for the toxicological evaluation of chemical sub- soil. Arch. Environ. in Contam. Toxicol., press. stances. Arch. Toxicol. 47: 77-99 (1981). 127. Huang, C.-Y., Bazzaz, F. A., and Vanderhoef, L. N. The 146. - Cairns, J., Jr., Biological monitoring. Part VI future inhibition of soybean metabolism by cadmium and lead. needs. Water Res. 15: 941-952 (1981). Plant Physiol. 54: 122-124 (1974). 147. Draggan, S., and Giddings, J. M. Testing toxic sub- 128. Premi, P. R., and Cornfield, A. H. Effects of addition of stances for of the protection environment. Sci. Total En- copper, manganese, zinc, and chromium compounds on viron. 9: 63-74 (1978). ammonification and nitrification during incubation of soil. 148. Stotzky, G., Babich, H., and Bewley, R. J. F. Application of Plant Soil 31: 345-352 (1969). the "ecological dose" concept to the impact of heavy 129. Bhuiya, M. R. H., and Cornfield, A. H. Incubation study metals on some microbe-mediated ecologic processes in on effect of pH on nitrogen mineralization and soil. Arch. Environ. in Contam. Toxicol., press. nitrification in soils treated with 1000 ppm lead and zinc, 149. Cornfield, J. Carcinogenic risk assessment. Science 198: as oxides. Environ. Pollut. 7: 161-164 693-699 (1977). (1974). 130. Horne, A. J., and Goldman, R. C. Suppression of nitrogen 150. Schneiderman, M. A., and Brown, C. C. Estimating cancer fixation by blue-green algae in a eutrophic lake with risks to a population. Environ. Health 22: Perspect. 115- trace additions of copper. Science 183: 409-411 (1974). 124 (1978). 131. metal soil Tyler, G. Heavy pollution and enzymatic activi- 151. Saffioti, U. Experimental identification of chemical carcin- Plant Soil 41: 303-311 ty. (1974). ogens, risk evaluation, and animal-to-human correlations. 132. Tyler, G. Heavy metal and mineralization of ni- pollution Environ. Health Perspect. 22:107-113 (1978). trogen in forest soils. Nature 255: 701-702 (1975). 152. Jacobs, L. G. Environmental 207: analysis. Science 1414 133. Tyler, G. Effect of heavy metal pollution on decomposi- (1980). tion and mineralization in forest soils. In: International 153. Munro, I. C., and Krewski, R. D. Risk assessment and reg- Conference on Metals in the Heavy Environment, ulatory decision making. Food Cosmet. Toxicol. 19: 549- Vol Symposium Proceedings, II, Part 1. Institute for 560 (1981). Environmental Studies, University of Toronto, Ontario, 154. Starr, C., and Whipple, C. Risks of risk decisions. Science Canada, 1975, pp. 217-226. 208:1114-1119 (1980). Tyler, G. Heavy metal pollution, phosphatase activity, 155. Rall, D. P. of Relevance animal experiments to humans. and mineralization of organic phosphorus in forest soils. Environ. Health Perspect. 32: 297-300 (1979). Soil Biol. Biochem. 8: 327-332 (1976). 156. Hoel, D. G. Animal experimentation and its relevance to 135. D. 0. Nitrification in Wilson, three soils amended with man. Environ. Health Perspect. 32:25-30 (1979). zinc sulfate. Soil Biol. Biochem. 9: 277-280 (1977). 157. Van Ryzin, J. Quantiative risk assessment. J. Occup. Med. 136. L. Albright, J., Wentworth, J. W., and Wilson, E. M. 22: 321-326 (1980). for 158. D. Technique measuring metallic salt effects upon the in- Gaylor, W., and Kodell, R. L. Linear interpolation algo- rithm for low digenous heterotrophic microflora of a natural water. dose risk assessment of toxic substances. J. Environ. Water Res. 6: 1589-1596 (1972). Pathol. Toxicol. 4: 305-312 (1980). 137. E. Landa, R., and Fang, S. C. Effect of mercuric chloride on carbon in mineralization soils. Plant Soil 49: 179-183 (1978).
Journal
Environmental Health Perspectives – Unpaywall
Published: Mar 1, 1983